The present invention relates in general to storing and retrieving information and in particular to storing and retrieving electronic television program guide data in a broadcast satellite system.
Television signal distribution systems typically broadcast television signals to individual users or subscribers on a plurality of individual television channels. The channels may be modulated onto one or more carrier frequencies within a discernable frequency band. Some wireless television signal distribution systems use one or more geosynchronous satellites to broadcast a broadband television signal to receiver units within a large geographic area, while other wireless systems are land-based, using one or more transmitters located within smaller geographic areas to broadcast to individual receiver units within those geographic areas.
The receiver unit receives and processes transmitted waveforms. The receiver unit in a satellite systems typically includes a satellite dish connected by a cable to an integrated receiver/decoder unit (IRD). The satellite dish is aimed toward the satellite, and the IRD is connected to the user""s television in a similar fashion to a conventional cable-TV decoder.
Along with the audio and video signals associated with the television channels, the satellite transmits various files such as text and graphics. These files and portions of these files may be used by the IRD to provide the user with additional information such as supplements to an electronic program guide. For example, a file may describe a particular actor or identify a movie""s director.
Typically, these files are stored in a relational database and retrieved by key fields. However, relational databases, particularly in an IRD environment, are slow and consume a large portion of RAM. Consequently, users must wait to retrieve program guide data and/or the cost of the IRD is increased by additional memory. Further, the names of the fields in the relational database (e.g., xe2x80x9cdirector) are typically fixed. New categories of information cannot be easily added after the IRD has been shipped.
Accordingly, the present invention provides a method and apparatus for dynamically naming and storing data using linked lists which consumes less memory is faster than traditional techniques. Further, the present method and apparatus allows categories of information to be created and deleted as needed, even after the IRD is shipped.
In accordance with one aspect of the invention, an apparatus for storing digital content records used to create informational displays in an electronic television program guide is disclosed. The apparatus comprises a satellite receiver for receiving a first content record, a memory for storing the first content record, and a control circuit operatively coupled to the receiver and the memory. The control circuit determines if the first content record is new, and if the first content record is associated with a label, wherein the label categorizes the first content record. The control circuit also determines if the first content record is associated with a title, wherein the title categorizes the label. Further, the control circuit sets a reference pointer associated with the first content record pointing to a referencing display object; and sets a first content pointer associated with the first content record pointing to a second content record associated with the label.
The receiver may be a direct to home satellite receiver. In some embodiments, the control circuit creates a new title comprising an array of linked lists or a linked list of linked lists. In such an instance, the control circuit may insert a head node into a linked list indicative of the label, and set a second content pointer in the head node pointing to the first content record. Further, the control circuit may set a second content pointer in a third content record pointing to the first content record.
In accordance with another aspect of the invention, a method is disclosed for storing digital content records used to create informational displays in an electronic television program guide. The method begins by receiving a first content record from a satellite receiver and determining if the first content record is new. Subsequently, the method determines if the first content record is associated with a label, wherein the label categorizes the first content record. Further, the method determines if the first content record is associated with a title, wherein the title categorizes the label. Further, the method sets a reference pointer associated with the first content record pointing to a referencing display object, and sets a first content pointer associated with the first content record pointing to a second content record associated with the label.